Tag keygen

The keygen tag was used to generate a key-pair (public/private key) as part of a form to facilitate client-side certificate generation and authentication. It would create a control that allows users to generate a cryptographic key pair and submit the public key to the server.

Basic Usage:

<form action="/register" method="post">
  <label for="keygen">Generate a key:</label>
  <keygen name="security_key" id="keygen">
  <input type="submit" value="Submit">
</form>
  • The browser would generate a public/private key pair when the form is submitted.
  • The private key is stored on the client side (usually in the browser or OS certificate store).
  • The public key is sent to the server.

Important Notes:

  • The <keygen> element is deprecated and removed from many modern browsers due to security and compatibility concerns.
  • It is not recommended for use in new projects.
  • The W3C HTML standard has removed it.
  • Modern applications use other methods for client certificate generation and authentication.

Alternatives:

  • Use JavaScript libraries for cryptographic key generation (e.g., Web Crypto API).
  • Use TLS client certificates managed outside of HTML forms.
  • Use OAuth or other secure authentication flows instead.